In this lesson, students explore a discrepant event when they design an experiment to measure the rate that ice melts when in pure water versus salt water. It is designed to help students realize that a carefully-designed experiment may yield...(View More) unexpected results, due to unseen events, even though the experiment is precisely planned and executed. The addition of a new technology may clarify factors in the experiment which were previously unknown. Note: the experiment requires advance preparation the day before: two buckets of water are set-up (one with plain tap water, the other with as much salt dissolved in it as possible), which need to be at room temperature. It also requires ice cubes of uniform shape (e.g., from an ice maker or ice trays filled to uniform capacity). This lesson is part of the Cosmic Times teachers guide and is intended to be used in conjunction with the 1993 Cosmic Times Poster.(View Less)

In this activity, students compare two images of the Crab Nebula taken more than 40 years apart. By measuring the motion of some of the knots of glowing gas in the neubla, students will be able to determine the date of the supernova explosion that...(View More) set the Crab Nebula into motion. This is Activity 2 of the "Supernova Educator's Guide" developed by the XMM-Newton and GLAST E/PO programs. The guide features background information, assessment rubrics, student worksheets, extension and transfer activities, and alignment to national education standards. Note: In 2008, GLAST was renamed Fermi, for the physicist Enrico Fermi.(View Less)

In this activity, students use rulers to measure distances between hypothetical galaxies and then use these distances to calculate the velocities of the galaxies. This activity is part of the "Cosmic Questions" educator's guide that was developed to...(View More) support the Cosmic Questions exhibit. This activity can be in conjunction with, or independently of, the exhibit.(View Less)

In this hands-on activity, students analyze the data on Mystery Object Cards, observe that astronomical objects have many observable properties, and discover that these properties allow scientists to categorize astronomical objects into different...(View More) groupings. Students also discover that, because objects can be grouped in different ways, discrete categorization is not always possible. This is why scientists need time to fully study and understand celestial objects and phenomenon. This activity is part of a unit designed to use gamma-ray bursts - unimaginably huge explosions that signal the births of black holes - as an engagement tool to teach selected topics in physical science and mathematics. The guide is based on the 5E instructional sequence and features background information, assessments, student worksheets, extension and transfer activities.(View Less)

Using a paper and tape device, students experience how atoms and molecules of gas in Earth’s atmosphere absorb electromagnetic energy through resonance. This activity is part of Unit 2 in the Space Based Astronomy guide that contains background...(View More) information, worksheets, assessments, extensions, and standards.(View Less)